Welded article



WELDED ARTICLE Franz iieitner, Kapienberg, Steiermark, Austria, assignor to Gebr. Biihler & Co. Aktiengesellachaft-Wien, Vienna, Germany No Drawing. Application March 16. 1937, serial No. 131,180. In Austria April is, 1936 This invention relates to welding, referring more particularly to a method of producin strong, sound ductile welds, free from'excessive slag inclusions, in nonaustenitic ferrous. metals, and to an improved weld Joint, so produced. possessing excellent bonding characteristics beim the base metal and the deposited filler ma- Chromium nickel alloy steel welding rods have 10 heretofore been used for welding austenitic and nonaustenitic iron and steel and ferrous alloysv by fusion deposition welding methods. In some of these austenitic chromium nickel steel welding rods, the nickel has been replaced in" whole or 5 in part'by manganese without greatly altering the austenitic structure of. the welding rod or of the .deposited filler metal.

When these well-known austenitic chromium steel alloys containing nickel or manganese or' both, are used for welding nonaustenitic ferrous metals, it is-possible to obtain sound welds substantiallyv free Iromblowholes and slag inclusions only by protecting the welding rod in some manner during deposition of the filler metal, and

' this isusually accomplished either by providing a protective coating on the outside of the rod or by enveloping the molten tillermaterial with a protective gas. Unless such precautions are used during the welding operation, the resulting weld metal is unsound and contains numerous slag inclusions, and the Joint between the tiller metal and the base metal is mechanically weak: the results of bend tests have shown that fracture occurs in such a weld at the junction of the filler 86 metal and the base metal'long' before the limit of ductility of the weld metal proper has been attained. v I have discovered that these serious diiiiculties can be eliminated by a method of welding wherein a flller'rod of. the following compodtion is employed, carbon in au'amount not exceeding 0.3%; 5% to 25% chromium; 3% to-2' I%'nickel 3% to 18% manganese; 0.3% to 6% molybdenum; 45 the remainder principally. iro Experiments have shown that a welding rod of this composition will produce a sound weld of excellent bondingcharacteristics between two or more contiguous members or nonaustenitic ferrous .metal. 50 Also the physicalproperties of both the deposited weld metal and the weld joint so produced are exceptionally good. Representative physical properties of samples of the welds made in accordance with this invention are as follows:

Maximum stress pounds per sq. mom-.- 92,450 5 Percent elongation .(L=5D) l 52 Percent reduction of 'area 55 Impact, strength (Mesnager). ft. lb./sq."

"cm Y 108 w 'The figures for maximum stress. elongation,

- and reduction of area were obtained by testing material of the welded joint contained 0.3% 15 carbon and 2.8% chromium and had a maximum strength of 102,000 lbs. per sq. in. The flller'rod applied had the following, composition: carbon 0.14%, manganese 7.5%, chromium 17.8%, nickel 7.6%, molybdenum 1.3%.

It can readily be seen from the results of these tests that the welds possess better physical prop erties than those hitherto obtained. These'results also show that a particularly good fusion contact has been obtained at the junction of the 25 weld metal and the'base metal.

The invention is applicable to both oxyacetylane and arc welding methods.

' The use of molybdenum as one of the constituso ents of the welding rod is of the utmost importance in securing a good bond between the base metal and the filler metal, so that the surface oi transition between the base metal and the filler metal is not a mechanically weak area.

In; the welding of the nonaustenitic ferrous metals it is sometimes necessary to increase the temperature of fusion of the welding rod toobtain'a particularly good fusion contact with the base metal. It .is within the invention toadapt the welding rods for such high temperature welding by the addition of one or more of alloying elements of the group consisting of vanadium,

titanium, tantalum, zirconium, cobalt and silicon in a total amount not exceeding 3% of the entire composition.

'It'is' also possible to. replace the molybdenum. -content} eitherwholly or in part; by tungsten.

. A few representative compodtions which I have found to make welding rods of excellent lwelding characteristics are as follows:

Carbon '0. 17% 0. 12% 0. 07%

* Chromium 20.00% 12.00% 18.00% Manganese 8.00% 1-1. 00% .6.00% Nickel 14. 00% 20.00% 10.00% Molybdenum: 2.50% 1.00% 4. Silicon 1.50%

Tungsten 2. 00% 0. 60%

I claim:

1. An article comprising at least two contiguous members of nonaustenitic ferrous metal bonded with a fusion deposited weld composed i of anjaustenitic steel containing carbon in an amount not exceeding 0.3%; 5% to 25% chromium; 3% to 27% nickel; 3%, to 18% manganese;

sarcomas 0.3% to 6% metal oi the group consisting of tantalum, zirconium, cobalt, silicon, the total amount of said metal or metals not exceeding 3% the remainder principally iron.

FRANZ 

